/*
* Copyright (c) 2006-2007 Erin Catto http:
*
* This software is provided 'as-is', without any express or implied
* warranty.  In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked, and must not be
* misrepresented the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* Converted for The Render Engine v2.0
* Aug. 4, 2010 Brett Fattori
*/

Engine.include("/physics/common/b2Settings.js");
Engine.include("/physics/common/math/b2Math.js");
Engine.include("/physics/common/math/b2Vec2.js");

Engine.include("/physics/collision/shapes/b2Shape.js");


Engine.initObject("b2ShapeDef", null, function () {

   var b2ShapeDef = Base.extend({

      type: 0,
      userData: null,
      localPosition: null,
      localRotation: null,
      friction: null,
      restitution: null,
      density: null,

      // The collision category bits. Normally you would just set one bit.
      categoryBits: 0,

      // The collision mask bits. This states the categories that this
      // shape would accept for collision.
      maskBits: 0,

      // Collision groups allow a certain group of objects to never collide (negative)
      // or always collide (positive). Zero means no collision group. Non-zero group
      // filtering always wins against the mask bits.
      groupIndex: 0,

      constructor: function() {
         this.type = b2Shape.e_unknownShape;
         this.userData = null;
         this.localPosition = new b2Vec2(0.0, 0.0);
         this.localRotation = 0.0;
         this.friction = 0.2;
         this.restitution = 0.0;
         this.density = 0.0;
         this.categoryBits = 0x0001;
         this.maskBits = 0xFFFF;
         this.groupIndex = 0;
      },
      
      ComputeMass: function(massData) {

         massData.center = new b2Vec2(0.0, 0.0)

         if (this.density == 0.0)
         {
            massData.mass = 0.0;
            massData.center.Set(0.0, 0.0);
            massData.I = 0.0;
         };

         switch (this.type)
         {
         case b2Shape.e_circleShape:
            {
               var circle = this;
               massData.mass = this.density * b2Settings.b2_pi * circle.radius * circle.radius;
               massData.center.Set(0.0, 0.0);
               massData.I = 0.5 * (massData.mass) * circle.radius * circle.radius;
            }
            break;

         case b2Shape.e_boxShape:
            {
               var box = this;
               massData.mass = 4.0 * this.density * box.extents.x * box.extents.y;
               massData.center.Set(0.0, 0.0);
               massData.I = massData.mass / 3.0 * b2Math.b2Dot(box.extents, box.extents);
            }
            break;

         case b2Shape.e_polyShape:
            {
               var poly = this;
               b2Shape.PolyMass(massData, poly.vertices, poly.vertexCount, this.density);
            }
            break;

         default:
            massData.mass = 0.0;
            massData.center.Set(0.0, 0.0);
            massData.I = 0.0;
            break;
         }
      }
      
   });

   return b2ShapeDef;
   
});
